1. Field of the Invention
This invention relates to the field of footwear, and in particular to a boot for skiing, having a sole attachable to a ski and an upper portion engaging the user's foot and lower leg.
2. Description of the Prior Art
Boots for skiing, skating and the like are intended to affix a user's foot and lower leg comfortably to a ski, rollerskate wheel chassis, ice skate blade or the like. Steering motions, namely tilting of the longitudinal axis of the lower leg from side to side over the ski or skate, must be accurately transmitted to the blade or wheel mounting for good steering control. Tilting motions forward and backward do not directly affect steering, but may have other effects. Fatigue can be reduced by use of a boot which provides some support in a forward-backward direction, allowing the user to assume a comfortable position, for example, leaning forward or backward against the resilience of the boot.
In order to convey side-to-side tilting movement precisely, the means of attachment between the ski and the user's lower leg must be substantially rigid in a side-to-side plane. The prior art includes ski boots adapted to attach a user's leg and a ski, using a hard sole block rigidly attachable to a ski and having structure for fixing the sole block with respect to a point on the user's shin, spaced from the ski. For the most part, such devices are standard boots having no specially-adapted means for fixing the user's foot and ankle with respect to the sole block and boot-leg, that improve over the usual foot-enclosing, shoe-like lacing or clamping structures well known in the art of shoes of the general-purpose variety.
Skate structures are most frequently simple shoes with extending uppers, the usual leather sole being more-or-less permanently attached to a metal blade-or-wheel support plate. Nevertheless, some of the same considerations apply to skis and skates. For purposes of convenience, the present application discusses the matter with respect to skis.
Ski boots having hard molded plastic shells have been known in the art for some years. These boots have means to rigidly attach a hard molded plastic structure to a ski, thereby providing a relatively rigid connection between the boot and the ski. A sole block is molded monolithically with an upwardly-extending shoe portion. The shoe may be integral with a lower-leg enclosure, or the boot may be articulated at the ankle. The leg or upper portion attachable to the user's foot and lower leg in the usual manner, i.e., the boot parts enclose the foot and leg. In an articulated structure, it is also known to provide adjustable spring biasing to set the extent to which the user can lean freely forward and backward on the ski.
Relatively rigid hard plastic material for ski boots and the like is a substantial improvement over previous materials, but the means for attaching such boots to the user's leg have not kept pace. Substantially the same attachment means employed with regular shoes are often applied to ski boots and skates. For example, regardless of use of hard shell material, ski boot structures often include flaps which, although themselves stiff, are brought together and/or caused to slide over one another as a means to reduce the circumference of a part of the boot to which the flaps are attached. The boot is cinched down on the user's foot or leg. This structure and the method of affixing a boot to a foot is much the same as bringing together opposite sides of a shoe by means of laces. Similarly, the prior art uses bails having a series of spaced attachment points, the bails being affixable to bring opposed portions of the boot closer to one another. Of course bail-type latching means and the like result in an attachment for the boot and leg that is rigidly fixed.
It is important in ski boots and ice skates to achieve a secure connection between the leg and boot in order to most effectively transmit the steering movements. Excessive tightening and/or cinching of boot portions without regard to the location of restrictions will impede blood circulation; inadequate tightening and/or misplaced restrictions will allow a relative displacement between the boot and the user's leg and/or foot, detracting from precision of steering movements. Users often also tighten the boots to reduce fatigue, i.e., using the rigidity of the boot to hold themselves in position with respect to the ski or skate.
It has been popular to attach a molded hard plastic boot to a user's foot by forming a custom-molded inner boot in a standard sized hard shell. The user's foot is used as a part of the mold, curable material being poured into a shell around the user's foot. The curable material conforms to the foot dimensions and the hard outer shell can be chosen from one of a series of standard dimensions. The moldable inner material is conveniently thermally-insulating and at least semi-rigid for support. Currently, foam pads in precise sizes are more popular than custom moldings mounted within hard outer shells. Such boots are similar to custom-molded inner boots in that correctly-sized semi-rigid insulating material is positioned between a hard shell of standard dimensions and the user's foot. The foam pad structure, however, does not require special molding equipment or the like in order to provide a custom fit. These methods and apparatus indicate the prior art's emphasis on precision of fit.
Whether made by molding or otherwise, custom boots may fit absolutely perfectly when made, but cannot remain perfect under even the best of conditions. Even a given user's foot will vary in size over time. Moreover, even assuming that such variations in size were minimal, the semi-rigid lining material will become worn and crushed during use as a result of the user's motions of walking, skiing, skating, etc. Normal use gradually enlarges the space allowed for the user's foot. Therefore, the prior art invariably also provided means for adjustably tightening the fit of even custom boots. Of course, greater tightening accelerates the wear on custom pads or molded forms.
Several known tightening means include bail devices, usually in the form of pivotal loops adapted to fit into any of the series of spaced hooks; adjustable pressure-exerting plates movable, for example, by means of screws; belt members extending through the surface of a boot and connecting an internal restriction to an external adjustment means, and the like. Adjustment means of the known kind are useful in allowing the user to offset changes in foot size due to swelling, shrinkage or boot wear, but the adjustment device itself increasingly becomes the structural attachment means by which the user's foot is attached to the ski. The prior art has conceived of various boot designs; however, it should be appreciated that the adjustment means is at least as important as the boot design because it will inevitably become a primary structural support.
Inadequacies and variations in fit are aggravated by closures or tighteners that must be set at a chosen one of a series of discrete intervals. The user may find that the boot is too tight at one position and too loose at the next. Similarly, the user may wish a tighter fit for some circumstances than for others. If the boot is set at the tighter of the available choices, the tightening mechanism rather than the remainder of the boot structure is the primary support that in the end must accomplish all the objects of the boot. The precision of the original fit is of no consequence.
If a boot is loose, the user loses a measure of control of steering the skis or skates, due to a loss of steady control over the precise tilt applied from side-to-side. As a further result of such looseness, a relative movement is permitted between the user's foot and/or leg and various members of the boot, thereby abrading the user's leg. This is particularly a problem between the front upper edge of a boot and the user's shin. Either a hard plastic portion or an insulating foam portion will cause discomfort if rubbed against the skin at the top edge of the boot. Relative movement can be minimized by tightening the boot, but if the boot becomes too tight, the user will be uncomfortable for that reason and may develop frostbite due to inadequate circulation. Whether too tight or too loose, poor fit also causes blisters.
The fit of ski boots affects the incidence of accidents. Loose boots are more difficult to steer, whereby the user is less able to avoid obstacles. Loose boots also do not support the wearer's bones and joints well during falls, leading to more frequent breaks and strains. A loss of circulation due to over-tightening can numb the user's feet resulting in frostbite. The numbness may also prevent the user from feeling subtle tactile clues such as differences between snow surfaces or the like.
The present invention provides a means by which the user's foot and lower leg are custom fitted to a relatively-rigid bottom and back portion of the boot, partially enclosing the user's foot and lower leg. This portion may be articulated, but in any case, the user's foot and lower leg are respectively attached to the sole and leg of the boot, and rigidly supported on the sole block in the side-to-side plane. A protective front portion closes the boot to snow and moisture. The foot is attached to the sole, and the leg to the back of the boot, by means of belts perpendicularly extending over the foot and leg, respectively, spaced from the ankle.
The front cover is preferably a flexible fabric that "breathes", i.e., allows water vapor to escape, such as that sold under the name Gore-tex. Unlike the prior art, the boot does not close tightly against the user's leg, but nevertheless provides full support. The bottom and back-mounted adjustment belts are continuously-adjustable rather than adjustable only at one of a series of discrete intervals. Preferably, the attachment belts both use hook and pile fasteners ("Velcro") or the like. A similar fastening means may be employed for the flexible front covering fabric. The attachment belts are fixed to the inner surfaces of the boot at spaced points, securing the user's foot and leg to the bottom and rear of the boot, respectively.
The structural and protective features according to the invention, but for the waterproof front fabric piece, are associated entirely with the rear/sole part of the enclosing structure. The user's leg can be spaced from the front to preclude abrasion. Problems with variation and fit are minimized.